title: Immune responses in infants whose mothers received Tdap vaccine during pregnancy.
abstract: BACKGROUND
  The effect of maternal Tdap vaccination on infant immunologic responses to routine pediatric vaccines is unknown.
  
  
  METHODS
  This was a cohort study of infants whose mothers received or did not receive Tdap vaccine during pregnancy. Maternal and cord blood samples were collected at delivery; infant blood samples were collected before and after primary series and booster dose of diphtheria, tetanus, and acellular pertussis (DTaP) and other vaccines. Geometric mean antibody concentrations or titers to pertussis, hepatitis B, tetanus, diphtheria, Haemophilus influenzae type b and polio antigens were measured. Mean maternal-to-cord blood antibody ratios were calculated.
  
  
  RESULTS
  At delivery, maternal and cord antibody concentrations to pertussis antigens were higher in the Tdap group (n=16) than control group (n=54; maternal: 1.9- to 20.4-fold greater; cord: 2.7- to 35.5-fold greater). Increased antibody concentrations persisted for infants at first DTaP (3.2- to 22.8-fold greater). After primary series, antibody concentrations to pertussis antigens were lower in Tdap group (0.7- to 0.8-fold lower), except for fimbriae types 2 and 3 (FIM) (1.5-fold greater). Antibody concentrations to pertussis antigens before and after booster dose were comparable (prebooster: Tdap group 1.0- to 1.2-fold higher than controls; postbooster: 0.9- to 1.0-fold lower). Differences in FIM values at these time points are difficult to interpret, due to varying FIM content among DTaP vaccines administered to infants in both groups.
  
  
  CONCLUSIONS
  Maternal Tdap immunization resulted in higher pertussis antibody concentrations during the period between birth and the first vaccine dose. Although slightly decreased immune responses following the primary series were seen compared with controls, differences did not persist following the booster.
authors.affiliation: From the *Dartmouth-Hitchcock Medical Center, Lebanon, NH; †University of Iowa Hospitals and Clinics, Iowa City, IA; ‡Geisel School of Medicine at Dartmouth, Hanover, NH; §Sanofi Pasteur, Swiftwater, PA; ¶Vanderbilt University School of Medicine, Nashville, TN; ‖University of Pittsburgh School of Medicine, Pittsburgh, PA; and **Cohen Children's Medical Center of New York, New Hyde Park, NY.
authors.forename: Abbey J
authors.initials: AJ
authors.lastname: Hardy-Fairbanks
authors.forename: Stephanie J
authors.initials: SJ
authors.lastname: Pan
authors.forename: Michael D
authors.initials: MD
authors.lastname: Decker
authors.forename: David R
authors.initials: DR
authors.lastname: Johnson
authors.forename: David P
authors.initials: DP
authors.lastname: Greenberg
authors.forename: Kathryn B
authors.initials: KB
authors.lastname: Kirkland
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Talbot
authors.forename: Henry H
authors.initials: HH
authors.lastname: Bernstein
mesh_terms: D000328:Adult; D000907:Antibodies, Bacterial / Q000097:blood*; D016022:Case-Control Studies; D022681:Diphtheria-Tetanus-acellular Pertussis Vaccines / Q000008:administration & dosage* / Q000276:immunology*; D005260:Female; D005312:Fetal Blood / Q000276:immunology; D006801:Humans; D007112:Immunity, Maternally-Acquired / Q000276:immunology*; D007223:Infant; D007231:Infant, Newborn / Q000276:immunology*; D011247:Pregnancy / Q000276:immunology*; D011297:Prenatal Exposure Delayed Effects / Q000276:immunology*; D014917:Whooping Cough / Q000517:prevention & control
chemical_list: D000907:Antibodies, Bacterial; D022681:Diphtheria-Tetanus-acellular Pertussis Vaccines